// Copyright 2016 The Draco Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#ifndef DRACO_COMPRESSION_ATTRIBUTES_SEQUENTIAL_ATTRIBUTE_DECODER_H_
#define DRACO_COMPRESSION_ATTRIBUTES_SEQUENTIAL_ATTRIBUTE_DECODER_H_

#include "draco/draco_features.h"

#include "draco/compression/attributes/prediction_schemes/prediction_scheme_interface.h"
#include "draco/compression/point_cloud/point_cloud_decoder.h"

namespace draco {

// A base class for decoding attribute values encoded by the
// SequentialAttributeEncoder.
class SequentialAttributeDecoder {
  public:
    SequentialAttributeDecoder();
    virtual ~SequentialAttributeDecoder() = default;

    virtual bool Initialize(PointCloudDecoder *decoder, int attribute_id);

    // Initialization for a specific attribute. This can be used mostly for
    // standalone decoding of an attribute without an PointCloudDecoder.
    virtual bool InitializeStandalone(PointAttribute *attribute);

    // Performs lossless decoding of the portable attribute data.
    virtual bool DecodePortableAttribute(const std::vector<PointIndex> &point_ids,
                                         DecoderBuffer *in_buffer);

    // Decodes any data needed to revert portable transform of the decoded
    // attribute.
    virtual bool DecodeDataNeededByPortableTransform(
        const std::vector<PointIndex> &point_ids, DecoderBuffer *in_buffer);

    // Reverts transformation performed by encoder in
    // SequentialAttributeEncoder::TransformAttributeToPortableFormat() method.
    virtual bool TransformAttributeToOriginalFormat(
        const std::vector<PointIndex> &point_ids);

    const PointAttribute *GetPortableAttribute();

    const PointAttribute *attribute() const {
        return attribute_;
    }
    PointAttribute *attribute() {
        return attribute_;
    }
    int attribute_id() const {
        return attribute_id_;
    }
    PointCloudDecoder *decoder() const {
        return decoder_;
    }

  protected:
    // Should be used to initialize newly created prediction scheme.
    // Returns false when the initialization failed (in which case the scheme
    // cannot be used).
    virtual bool InitPredictionScheme(PredictionSchemeInterface *ps);

    // The actual implementation of the attribute decoding. Should be overridden
    // for specialized decoders.
    virtual bool DecodeValues(const std::vector<PointIndex> &point_ids,
                              DecoderBuffer *in_buffer);

    void SetPortableAttribute(std::unique_ptr<PointAttribute> att) {
        portable_attribute_ = std::move(att);
    }

    PointAttribute *portable_attribute() {
        return portable_attribute_.get();
    }

  private:
    PointCloudDecoder *decoder_;
    PointAttribute *attribute_;
    int attribute_id_;

    // Storage for decoded portable attribute (after lossless decoding).
    std::unique_ptr<PointAttribute> portable_attribute_;
};

}  // namespace draco

#endif  // DRACO_COMPRESSION_ATTRIBUTES_SEQUENTIAL_ATTRIBUTE_DECODER_H_
